Pile fabric and the manufacture thereof



July 10, 1956 J. J. REPP 2,753,614

FILE FABRIC AND THE METHOD OF MANUFACTURE THEREOF Filed Sept. 17, 1949 FIG.I

INVENTOR JOHN J REPP RNEY PILE FABRIQ AND THE MANUFACTURE THEREOF John J. Repp, Philadelphia, Pa., assignor to Collins & Ailtman Corporation, Philadelphia, Pa., in corporation of Delaware Application September 17, 1949, Serial No. 116,347 5 Claims. (Cl. 23-43) This invention relates to the production of yarns or threads especially suitable for pile yarns of pile fabrics and to the pile fabrics produced therewith. More particularly the invention is directed to the production of pile fabrics in which the pile face is formed wholly or in predetermined parts of ply pile yarns which do not lose their visual identity in the fabric after cutting, processing and considerable use.

Prior to the present improvements, the pile portion of cut pile fabrics has been formed from high twisted yarns or over twisted ply yarns which were not brushed or greatly disturbed prior to marketing and use. It has been proposed to avoid the known defects of some pile fabrics containing such tightly twisted cut pile threads by using crepe threads which are not cut but form spiralized" uncut loops. These uncut pile fabrics are woven differently and have a different appearance and feel than those such as are woven on double shuttle looms and cut apart in a known manner.

Curled mohair pile fabrics and floor coverings are also well known. The mohair pile yarns are conventionally set by several hours treatment in boiling water. The required treatment, as represented above, is known to materially damage the mohair fibers and this, together with variations in quality of stock results in a very low loom efiiciency for fabrics of this type. Efiiciencies of 40% are not uncommon.

Furthermore despite the curl conformation in addition to normal twist the permanency of the curl is not all that could be desired.

The above, and other prior art procedures involving twisted cut pile effects of which I am aware, have one or more deficiencies such as damage to the fibers, the initial set being not sufiiciently permanent against high temperature treatments, wet treatments, rubbing or wear. These prior art products have, however, received a degree of trade acceptance because of the pleasing effects attained. in the floor covering field it is believed that this acceptance has been limited to natural animal fibers such as curled mohair and a few specially prepared carpet wool yarns.

According to the present improvement there are provided nylon yarns, and in some cases yarns of animal fibers such mohair blended with nylon, preferably made from all spun staple fibers, and which may be of relatively low twist. These yarns are woven into upholstery and floor covering fabrics and do not lose their identity in the fabric after cutting to form cut pile not after Wet or steam processing and extended use. In fact, hot wet treatments such as occur in passage through a dyebath and associated squeeze rolls appear to materially improve the appearance of the pile which may have been somewhat distorted from cutting or rough handling.

The pile yarns are prepared by high temperature treatment as will be more fully set forth. They are characterized by what might be termed a thread set in which the individual fibers are given a predetermined relative setting to each other, so that regardless of the particular nited States Patent 0 configuration of a leg, each fiber will tend to maintain it. In all cases the fabrics produced differ substantially in face appearance from the usual velvet or velveteen fabrics. They appear coarse because of the yarn set. Straight legs produce a pebble like effect. The crimped or curled fabrics are more irregular as the ends of the legs are not all exposed.

The pile is made up of legs as opposed to opened up tufts as will be hereinafter more fully shown With reference to the drawings, Figs. 2-5. The legs are formed from separate plies twisted together along their length. Each ply contains resilient synthetic polyamide staple fibers which are set in the ply form in a predetermined configuration. The synthetic polyamide fibers are truly resilient and each has a relative setting Within the yarn to which setting they individually tend to return after wear or other deformation. This tendency is accelerated by wet treatment. Synthetic polyarnide oriented fibers are disclosed in Patents 2,071,250, 2,071,251, 2,071,253 and 2,130,948 to Carothers. These fibers have gone into extensive use under the generic name nylon fibers. Nylon fibers are sometimes referred to as superpolyamides. They have considerably more resistance to heat and moisture than do mohair or wool. The melting points vary considerably, the present invention being concerned with those having a melting point of from 275 F. to 600 F., about 480 F. being typical of the melting point of the commercial fibers used in fabrics woven. in accordance with this invention. Hot air settings for these fibers should not greatly exceed 440 F It has previously been proposed that pile fabrics be made with continuous filament nylon. Also crush proofing by atmospheric steaming has been suggested. The products described herein differ materially from prior art products and specifically from the velvet or fur like nylon fabrics of the prior art.

In the instant case, while the nylon staple may be and frequently is crimped to aid in the spinning, a substantial portion of this crimp is removed in the processing required for this invention. Also the present improvements differ from fabrics using specially prepared spontaneously crimpable nylon fibers such as would produce a homogeneous wool like face.

A filament yarn may be doubled or piled with spun staple yarn although all spun staple plies are preferred. As mentioned above, the weaving efficiency of curled mohair is very low. 1 have found that if a relatively small percentage of synthetic polyamide fibers are spun together with mohair the yarn may be curled and the weaving etficiency greatly increased. If the percentage is in the neighborhood of 10% or less no provision need be made for dyeing the nylon. Depending on the quality of mohair amounts up to 30% may be used for purposes of strengthening mohair yarns. The nylon fibers will assume a set under the conventional mohair processing. In the 30% blend a uniform color and appearance may be obtained without undue difficulty. The setting does not in any noticeable way damage the nylon. It is not, however, the preferred setting as superior results are obtained by heat or steam settings in which the temperature attains approximately 275 F. for a period of about 20 minutes or a higher temperature up to about 440 F. with sharply reduced time. Mohair or wool cannot be sub jected to such treatment without excessive damage. At a temperature of 275 F., for example, the time may, according to the invention, be reduced to as low as about 3 minutes. The resultant fabrics are comparable in appearance to commercial curled mohair fabrics, but the eifect is somewhat less distinct than if set in the preferred manner. The intimate blending of the animal fiber and nylon is much preferred over the use of single ends of each because of dyeing and setting considerations, except where a mottled effect is desired.

An object of the present invention is to provide improved pile fabric yarns and pile fabrics.

Another object is to provide a heat set pile ply yarn which is given a permanent and resilient set capable of reasumming its set position or stand in the fabric after liquid treatment.

Another object is to provide a nylon type pile fabric in which the face has either a pebble like appearance or a curled yarn appearance or combination of both.

Another object is to provide a method of producing novel nylon pile fabrics.

These and other objects will be manifest from a con sideration of the following description, claims and drawings in which:

Fig. 1 is a back view of a rubber or otherwise coated V pile fabric with the spacing exaggerated to show the construction and the adhesive restricted to a section.

Figs. 2, 3 and 4 are illustrations of configurations taken by individual 2 ply legs in the fabric of Fig. 1 with an enlarged weft to better illustrate the leg formations.

Fig. 5 illustrates a straight three ply leg 3 and its associated weft.

According to the invention upholstery fabrics may vary in pile height from approximately V to /5 inch, whereas the pile height of floor covering will approximate to A3 inch. It is to be noted that the size of the nylon fibers may correspond closely with that of the usual natural staple fibers used in similar weaving constructions and that resort need not be made to the use of uncommonly heavy fibers unless this is desired.

In short, so far as diameter of fibers is concerned an unusually wide choice is provided as the limitations of natural fibers are not present. With respect to twist a definitely superior product to those produced from natural fibers is produced with the same or lower twist. This is rather dramatically illustrated with respect to curled products where a spun nylon curled carpet of the invention showed a wear resistance (abrasion as determined by a Taber Abrader Machine) twelve times as great as a similar mohair curled fabric of like count construction and of commercial quality. The fabrics of the present invention may have considerable variation in the ground weave both as to material and construction. The pile may be a V pile, W pilc, Wilton type or other type pile and affords excellent coverage of the ground in any of these constructions. in the case of the curled yarns the backing coverge is aided by the lay of the pile which may be secured adhesively as by an elastomer such as rubber or by yarn interlacing.

The particular fabrics compared were both v pilc fabrics in which the tufts were secured to the backing by a rubber adhesive composition. The pile in each case was two ply 10s worsted count and the single nylon ends of one fabric were 8.5 denier crimped fibers spun into staple fiber yarns. The mohair fibers were of comparable size.

In the drawings Fig. 1 shows a ground formed by warp threads 1 weaving in flats over weft threads 2 so as to provide lateral support for both sides of tufts 3. The tufts 3, depending on the weave may be secured to the backing by adhesive 4 such as a water insoluble elastomer, rubber type compositions including sponge rubber being illustrative. Curling greatly simplifies the anchorage problem of V pile nylon upholstery fabrics.

Nylon fibers if untwisted and subjected to wet heat treatment above boiling will shrink approximately 8 to 14 percent depending on the temperature. While this shrinkage may be retricted to lower percentages by strong confining action it is preferred that some shrinkage be allowed as this has certain advantages including increasing the affinity of the fibers for most dyestuffs used. Shrinkage with curling will result if a group of ply nylon yarns, say 20 or 30, are twisted on each other to form a curl in the individual yarns and the yarns are then subjected to saturated steam at 30# gauge for a period of twenty to thirty minutes. Preferably alternate steaming and vacuum are used to insure penetration of the steam and eliminate faults clue to locked in air. The legs illustrated in Figs. 2, 3 and 4 resulted from this type treatment.

The yarns are preferably cooled or allowed to cool before packing after setting and curling or after setting if curling has not been included. Curling definitely aids the permanency of the effects and permits use of a lower twist in the singles or ply or a shorter setting time. Filament yarns are not so desirable as the spun yarns and while the reason is not entirely clear it is believed that the shrinkage characteristics of the nylon fibers during setting are at least partly responsible for the difference. Filament as opposed to spun nylon may be used, as a ply, in three or more ply yarn where the yarn is set, but not curled as described above. Novel effects may also be obtained by use of lower than usual twists for straight legs, the amount of twist depending on the desired elfect.

The pile legs of the fabrics of the present invention are characterized by a distinct tendency to recover their original set position when reduced to short length as in the case of cut V or W pile fabrics when subjected to short or long time hot liquid treatments as in pad or kettle dyeing. Dislocation of the pile as in dyeing appears to actually assist the uniformity of the method, pebbled, crimped or curled effect resulting from the original set prior to Weaving.

The fibers are preferably synthetic thermoplastic polyamides which have been fully drawn to a state of true elasticity as undrawn or partially drawn fibers are difficult to handle through processing and on complex pile fabric looms.

The time and setting temperature may be varied to suit conditions of the setting treatment, such as whether the treatment he in air or steam. Saturated steam treatments may include temperatures near the melting point whereas air treated yarns should not be subjected to temperatures greatly exceeding 440 F. for those fibers having a melting point about 480 F. In the case of straight or uncurled yarns, i. e. those which do not have regularly formed curls or crimps at regular short intervals the setting treatment may be applied in skein form or otherwise so as to allow shrinkage. The crimps or curls need not be for the entire length of any single yarn.

The term crimped as used in the claims covers helical, diamond or other curls as well as gear type crimp. The preferred setting is high temperature setting wherever possible as in all nylon pile yarns.

Normal wear as used herein means sitting wear in the case of upholstery fabrics or walking wear in the case of floor covering.

Pile yarns made from nylon fibers having a melting point of approximately 480 F. and which have been set at 275 F. or more as above described appear to give a more satisfactory result than when these yarns are set at lower temperature. Lower temperatures in ascending scale consume considerably more time in obtaining reasonably similar results and are deficient with respect to etficient removal of the fiber crimp usually introduced to facilitate the spinning of staple fibers of this type.

It will be understood that the 2/ 10s worsted count curled yarn above referred to and 3/ 37s carpet count 3 ply twisted yarns which may be used as pile are merely illustrations of the size of pile yarns which may be used. A possible twist construction of the three ply yarn is 5 turns per inch in the single ends and 8 turns per inch in the ply. The legs will be positioned in the fabric so as to completely conceal the ground.

As stated above, with the more usual synthetic linear polyamide fibers which have a melting point of approximately 480 F. it is preferred that setting temperatures 5 be 275 F. to 440 F. Above 440 F. problems resulting from air and other damage arise and steam producing such temperatures necessitates very high pressure vessels. The preferred temperature includes a con siderable temperature zone at which the fibers become sticky. In most instances this does not cause interfiber adherence after cooling. It will be understood that some sticking of fibers where material damage is not involved is not objectionable and is advantageous in some respects.

Other synthetic fibers including cellulose acetate, viscose, cupra-ammonium rayon and low melting point fibers capable of being cold drawn and receiving molecular orientation by such drawing are not suitable for the practice of the invention, although some of these fibers are capable of being shaped by heat treatment. Polyethylene terephthalate cold drawn oriented fibers having a melting point above 275 F. are of limited application.

Crimped yarns are superior to other twisted yarns insofar as coverage of the ground is concerned as their random positions give excellent and complete coverage with a relatively small amount of pile. The fabrics of the invention are soil resistant and readily cleaned.

This is particularly true of the crimped pile as the dust and dirt may settle to the backing and are easily removed by a vacuum cleaner while the legs are relatively straight.

Having described my invention in connection with preferred embodiments I claim:

1. In a process of manufacturing cut pile fabrics the steps comprising forming twisted yarns each including staple synthetic polyamide fibers, forming a ply yarn by twisting said yarns together, deforming the ply twisted yarns by twisting a plurality of ply yarns together, setting the deformed yarns, weaving a ply yarn so formed in a pile fabric and cutting the pile.

2. A fabric made by the process of claim 1.

3. The fabric of claim 2 wherein the said twisted yarns consist solely of staple synthetic polyamide fibers.

4. The fabric of claim 2 wherein the said twisted yarns include mohair fibers.

5. The fabric of claim 2 wherein the twist forming the said ply yarn is a substantially light twist.

References Cited in the file of this patent UNITED STATES PATENTS 1,661,018 Stroud Feb. 28, 1928 2,157,117 Miles May 9, 1939 2,147,118 Heckert May 9, 1939 2,238,098 Bradshaw Apr. 15, 194.1 2,430,425 Jackson Nov. 4, 1947 2,509,347 Jackson May 30, 1950 2,509,348 Jackson May 30, 1950 2,509,349 Jackson May 30, 1950 2,509,350 Jackson May 30, 1950 2,509,351 Reinhardt et a1. May 30, 1950 2,509,352 Reinhardt et a1. May 30, 1950 2,557,453 Miller June 19, 1951 FOREIGN PATENTS 2,247 Great Britain 1881 3,054 Great Britain 1880 4,206 Great Britain 1880 137,470 Austria May 11, 1934 514,821 Great Britain Nov. 20, 1939 520,323 Great Britain Apr. 19, 1940 561,769 Great Britain June 5, 1944 OTHER REFERENCES The New Fibers, by Sherman and Sherman, published 1946 by D. Van Nostrand Co., New York; page 61. 

1. IN A PROCESS OF MANUFACTURING CUT PILE FABRICS THE STEPS COMPRISING FORMING TWISTED YARNS EACH INCLUDING STAPLE SYNTHETIC POLYAMIDE FIBERS, FORMING A PLY YARN BY TWISTING SAID YARNS TOGETHER, DEFORMING THE PLY TWISTED YARNS BY TWISTING A PLURALITY OF PLY YARNS TOGETHER, SETTING 